Clinical ScienceA negative urinalysis is associated with a low likelihood of intra-abdominal injury after blunt abdominal trauma

- The urinalysis has high sensitivity for injuries after blunt abdominal trauma.
- The presence of any red blood cells per high-powered field considered positive.
- Observation patients with a negative urinalysis and no other indications for abdominal imaging.

BackgroundThe utility of urinalysis (UA) to diagnose intra-abdominal (IA) or genitourinary (GU) injury after blunt trauma remains controversial. The purpose of this study was to determine the significance of UA in the blunt trauma patient.MethodsA retrospective review of patients admitted for blunt abdominal trauma from 2011 to 2013.ResultsA total of 1,795 patients sustained blunt abdominal trauma: mean age of 44 ± 21 years; mean Injury Severity Score of 13 ± 10. Overall 810 patients had a negative UA (45%). Two patients (2/810 and .2%) had a GU injury and neither required intervention. Thirty-two patients (32/810 and 4.0%) had an IA injury, and 2 (2/810 and .02%) required intervention. The sensitivity for predicting GU injury requiring intervention was 1, and IA injury requiring intervention was .96. Negative predictive values were 1 and .99.ConclusionsA negative UA correlates with a low risk for GU and IA injury after blunt abdominal trauma. A negative UA should be evaluated prospectively as part of a clinical prediction score to rule out injury and avoid unnecessary radiation exposure from computed tomography imaging.